Best adhesive for duplexing handmade papers?

I’ll be duplexing sheets of handmade paper for an upcoming project and my research has brought varied results regarding the best adhesive for the job. The paper is 110 lb. and pretty smooth considering its recycled makeup.

If I had to choose the best adhesive for duplexing, between PVA or 3M spray glue….. I’d have to say “none of the above”

While they both will work, they are not the best adhesives. They are messy, and often only produce mediocre results. I used to use PVA myself…… but was never satisfied by the quality of the finished product.

For he last decade of so, I’ve been using Nori, and it works like a charm.

What is Nori? you might ask. Nori is rice or wheat starch paste….. the same stuff used by traditional bookbinders, and sometimes used for wallpaper. It has less moisture than PVA, and thus has less tendency to cause buckling, it is easy to use, and is very inexpensive. PLUS, unlike the glues you mention, it is archival…. so the work you produce will not turn brown in a few years.

You can get it pre-prepared at the art supply house, or you can do like I do and prepare it yourself. There are several good recipes on the Internet.

I have to respectfully point out one of Nori’s qualities that is NOT desirable (or at least, may not be in this case).
There are a few different things that make a substance “archival”- yes, PH Neutrality is one thing, but another is- does the substance allow for repairs?
In the case of bookbinding, Nori is prized because you can Un-do it if needed. It is reversible.
Nori can be undone with moisture, and even sometimes humidity to a high degree (or steam, etc)

When duplexing stock together with the end result being a printed object that will be handled- one might not want the adhesive to let go?

I duplex a lot, I use PVA (heat sealable, reversible, buffered)
in gluing machine which allows me to lay down a super thin Film of PVA, immediately pressed I have not experienced
buckling or separation, this is duplexing in large numbers with fiber based stock and usually digital printing.
Than I duplex fiberbased Paperstock which is printed Letterpress or Gravure and has deep impression, I mix the PVA with 50 % Paste (Planatol) and let the suction of the Paste pull the sheets together, rather than pressing it.
Proper duplexing is based on knowing the paper stock to be used and and it’s applied behavior. Any adhesives, Pastes or glues need to be tested, as you can’t duplex something which than sits under Lights in a Exhibition case and due to the heat applied, starts to delaminate.

Good Morning HP…. You make valid points but my experience has been that Nori based duplexing doesn’t have any real issue with delamination due to humidity.

Here is what I’ve learned / read/ discovered about Nori:

1. Nori is indeed ph neutral, and archival in nature. Many, many thousands of books, boxes, duplexed papers and so forth have stood the test of time for hundreds of years without showing any signs of degradation from the paste.

2. It was the adhesive of choice for duplexing from the 1400’s up until the 1950’s and experience has shown that it does not have a tendency to come unglued with humidity changes over many decades. Papers I did back in the 1970’s are still tight after much handling…. even paperback book covers. (That being said, it does not stand up well to total immersion or a good soaking…. but neither does paper in general.)

3- most importantly, it has a lower moisture content than PVA and thus has a far less tendency to cause buckling / blistering / wrinkling and so forth.

4. related to the above, Nori does not create an impermeable barrier between layers like PVA or solvent based adhesives do, and again this lessens the likelihood of the document curling due to differential expansion from one layer being more exposed to moisture than the other side…. like when it lays in a stack, or on a flat surface.

5- Unlike PVA, the expansion / contraction rate of Nori is the same as the paper it is applied to. Again, this helps prevent buckling / curling / delamination.

6- it’s very inexpensive…. for about $5 you can buy enough ingredients to last you for at least a year.

SO…. does it have disadvantages? Yes it does…

1- most folks don;t understand it nowadays and/or haven’t tried it…. and thus there is not a large body of online user instruction on how to use it correctly.

2- you do have to make it just before you use it and that does take an hour or so….. once made it will only last in a moist state for a few days before it molds or goes stinky.

3- it does not lend itself well to rolling onto the paper. It’s too stiff. It needs to be applied with a brush.

4- thick papers duplexed with Nori do not fold as well as those done with PVA. This is only an issue if you don’t score it first.

Items 2 and 3 are probably the main reasons it was not adapted for machine application like PVA was….. and that is reasonable. Nori / starch paste is a bit more labor intensive, so if you are doing hundreds of pieces where labor costs are a factor then you might want to use PVA, but if you are willing to do the extra work to use Nori, you’ll wind up with a neater finished piece that is nicely stable, and lasts for many, many years.

The real truth is however that either PVA or Nori will work if used correctly. With any adhesive, I’d follow the recommendation from Typenut to test and experiment with your glue before deciding on which one to use. Then pick the one that gives you the best results.